Electrical Potential
المؤلف:
GEORGE A. HOADLEY
المصدر:
ESSENTIALS OF PHYSICS
الجزء والصفحة:
p-326
2025-11-29
16
Demonstration. - Charge two insulated conductors - tin cans upon glass tumblers will do - with the glass rod, and connect one of them with a gold-leaf electroscopе by means of a piece of wire provided with an insulating handle. Notice the extent to which the leaves separate. Remove the wire from the body and discharge the electroscope. Connect the electroscope with the second body, and notice the divergence of the leaves. Now connect the two charged bodies by a conductor and notice that if the divergence of the leaves of the electroscope was less when connected with the second body than when connected with the first, they will now diverge more widely than before when connected with the second, and vice versa. On connecting the electroscope with the first body it will be found to give the same divergence as the second.
From this demonstration we conclude that there has been a flow of electricity from the body giving the greater divergence of the gold leaves to the other. This condition of electrified bodies which sets up an electric current in a conductor which connects the two bodies is the difference of potential or the P. D. of the bodies.If the e
r, showing that the electroscope is discharged. The quantity of electricity in the body is so small that it does not, on being connected with the earth, change the condition of the earth in any perceptible degree. The earth is for the sake of reference - assumed as the zero of potential, bodies positively charged being considered at a higher potential than the earth, while those negatively charged are at a lower potential than the earth. If the difference of potential between two bodies is kept constant, the current passing
in the conductor that joins them will be a continuous current. If the P. D. is not maintained, the current will be only momentary.
Potential is analogous to water pressure, and the current to the flow of water that takes place in a pipe connecting two bodies of water at different levels. The position of the water of a water tank with respect to the surface of the earth would be positive: the water would run from the tank to the earth. The position of the water in a well would be negative: the water would flow from the surface into the well.
lectrified body connected with the electroscope is now connected with the earth, the leaves will at once fall togethe
الاكثر قراءة في الكهربائية
اخر الاخبار
اخبار العتبة العباسية المقدسة
